1. Field of the Invention
The invention is in the field of electronic devices and more specifically in the field of radio frequency identification (RFID) tags.
2. Description of Related Art
RFID tags are typically small, flexible, and low profile devices that can be affixed to items for electronic tracking and information storage purposes. An RFID tag can be read by an RFID reader when the RFID tag is brought within a certain vicinity of the reader while the reader is broadcasting an appropriate signal. In some cases, once within that vicinity, the RFID tag receives sufficient power from the broadcast signal to permit the RFID tag to transmit a return radio frequency signal. This type of RFID tag is referred to as a passive RFID tag because it does not include an independent power source. Passive RFID tags may receive power either via a radio frequency signal (e.g., radio waves) or through electromagnetic induction. Typically, electromagnetic induction is easier to implement but operates over a shorter range. Electromagnetic induction may operate at lower frequencies than RF powered RFID tags. In other cases an RFID tag includes an independent power source for generating a radio frequency signal. This type of RFID tag is referred to as an active RFID tag.
RFID tags generate a return radio frequency signal that may include an encoded copy of information stored within the RFID tag. As RFID tags achieve more wide spread use they will become ubiquitous on forms of tagging, labeling, identification, and be included in personal and business effects, such as passports, driver's licenses, keys, cell phones, credit cards, PDAs, and so forth. For example, an RFID tag may be incorporated in a driver's license to store personal information about the licensee or in a product label to track inventory.
A problem with using RFID tags to store security, confidential and/or personal information is that an RFID reader can read any RFID tags that pass within its range. Even if data is encrypted, this creates a possibility of unauthorized access to the personal data and other information stored in the RFID tag.